岩石中微生物学研究的分子生物学技术——中国大陆科学钻探（CCSD）微生物研究

本文介绍了中国大陆科学钻探（CCSD）微生物学研究中所建立起来的分子生物学技术，即环境基因组DNA提取、16SrDNA分析、Real-timePCR技术和磷脂酸分析技术。另外探索了防污染的手段以及监测方法，并介绍了我们以这种方法对CCSD的微生物学研究所得到的一些初步结果。     

聚乙二醇硝化菌包埋固定化技术研究及应用

近年来,在固定化微生物处理污水方面国内研究报道逐渐增多,人们对于包埋材料也进行了多方面的探索,如琼脂,海藻酸钠,聚乙烯醇(PVA)等均见到相关研究报道,但是使用聚乙二醇(PEG)作为包埋材料的介绍比较少见,在国外,使用聚乙二醇(PEG)包埋固定化硝化菌的产品已经有了投放市场的产品。国内也有部分的研究。本文目的在于介绍该款产品在国内外研究及应用状况,期望能为国内同行提供参考。     

Hydrochemical and microbiological quality of groundwater in West Thrace Region of Turkey

The aim of this study was to do a preliminary assessment of the hydrochemical and microbial groundwater quality of the West Thrace region. Forty samples of groundwater collected from Edirne (Site 1) to Gelibolu (Site 2) were assessed for their suitability for human consumption. As³⁻ was non-detectable in all the groundwater and Zn²⁺, Pb²⁺, F⁻, Cu²⁺, NH₄⁺, Cn⁻ PO₄³⁻ and Cl⁻ were all below their respective European Union drinking water directive (EU-DWD) and Turkish food codex-drinking water directive (TFC-DWD). Maximum Acceptable Concentrations (MAC) Ni²⁺, Pb²⁺, Cd²⁺, Mg²⁺, Mn²⁺, and Ca²⁺ levels were detected in upper maximum acceptable concentrations 77.5, 42.5, 35.0, 50.0, 50.0, and 32.5% of the groundwater samples, respectively. However, in terms of Cr³⁺, Ni²⁺ and Pb²⁺, the differences between groundwaters of Sites 1 and 2 were significant (p < 0.05). Eight water samples (20%) had HPC exceeding the EU and Turkish water directive limit 20 CFU (Colony Forming Unit)/ml in drinking water and the maximum bacteria count recorded was 44 CFU/ml. Total coliforms, thermotolerant coliforms, E. coli, Enterococcus spp., Salmonella sp., Staphylococcus spp. and P. aeruginosa were detected in 25, 17.5, 15, 47.5, 15, 27.5, and 15% of the groundwater samples, respectively. Furthermore, heavy metals and trace elements were found after chemical analyzes in most samples. The pollution of groundwater come from a variety of sources, Meric and Ergene rivers, including land application of agricultural chemicals and organics wastes, infiltration of irrigation water, septic tanks, and infiltration of effluent from sewage treatment plants, pits, lagoons and ponds used storage.     

Ballast water as a vector of coral pathogens in the Gulf of Mexico: the case of the Cayo Arcas coral reef

The discharge of nutrients, phytoplankton and pathogenic bacteria through ballast water may threaten the Cayo Arcas reef system. To assess this threat, the quality of ballast water and presence of coral reef pathogenic bacteria in 30 oil tankers loaded at the PEMEX Cayo Arcas crude oil terminal were determined. The water transported in the ships originated from coastal, oceanic or riverine regions. Statistical associations among quality parameters and bacteria were tested using redundancy analysis (RDA). In contrast with coastal or oceanic water, the riverine water had high concentrations of coliforms, including Vibrio cholerae 01 and, Serratia marcescens and Sphingomona spp., which are frequently associated with “white pox” and “white plague type II” coral diseases. There were also high nutrient concentrations and low water quality index values (WQI and TRIX). The presence of V. cholerae 01 highlights the need for testing ballast water coming from endemic regions into Mexican ports.     

A large volume particulate and water multi-sampler with in situ preservation for microbial and biogeochemical studies

A new tool was developed for large volume sampling to facilitate marine microbiology and biogeochemical studies. It was developed for remotely operated vehicle and hydrocast deployments, and allows for rapid collection of multiple sample types from the water column and dynamic, variable environments such as rising hydrothermal plumes. It was used successfully during a cruise to the hydrothermal vent systems of the Mid-Cayman Rise. The Suspended Particulate Rosette V2 large volume multi-sampling system allows for the collection of 14 sample sets per deployment. Each sample set can include filtered material, whole (unfiltered) water, and filtrate. Suspended particulate can be collected on filters up to 142 mm in diameter and pore sizes down to 0.2 μm. Filtration is typically at flowrates of 2 L min⁻¹. For particulate material, filtered volume is constrained only by sampling time and filter capacity, with all sample volumes recorded by digital flowmeter. The suspended particulate filter holders can be filled with preservative and sealed immediately after sample collection. Up to 2 L of whole water, filtrate, or a combination of the two, can be collected as part of each sample set. The system is constructed of plastics with titanium fasteners and nickel alloy spring loaded seals. There are no ferrous alloys in the sampling system. Individual sample lines are prefilled with filtered, deionized water prior to deployment and remain sealed unless a sample is actively being collected. This system is intended to facilitate studies concerning the relationship between marine microbiology and ocean biogeochemistry.     

长江口及其附近海域细菌和三磷酸腺苷的分布特征

于1986年1月和7月在长江口及其附近海域进行了细菌的落射荧光直接计数和三磷酸腺苷(ATP)浓度的测定,同时取分样进行了微生物呼吸作用耗氧速率和叶绿素浓度的测定。结果表明,细菌数量和ATP浓度夏季较冬季高,总的分布趋势是,高值区出现在内河段和长江口,向外海逐渐降低;细菌数同悬浮体浓度、硝酸盐浓度和耗氧速率呈正相关,与盐度呈负相关。冬季,在整个海域细菌是ATP的主要贡献者和溶解氧的主要消耗者;夏季,沿冲淡水方向ATP出现两个峰值,第一峰值出现在长江口的最大浊度带,由细菌所贡献;第二个出现在盐度25—30的区域,由浮游植物所贡献。呼吸作用耗氧速率也呈现了与ATP相似的分布特征。     

An astrobiological perspective on Meridiani Planum

Sedimentary rocks exposed in the Meridiani Planum region of Mars record aqueous and eolian deposition in ancient dune and interdune playa-like environments that were arid, acidic, and oxidizing. On Earth, microbial populations have repeatedly adapted to low pH and both episodic and chronic water limitation, suggesting that, to a first approximation, the Meridiani plain may have been habitable during at least part of the interval when deposition and early diagenesis took place. On the other hand, the environmental conditions inferred for Meridiani deposition would have posed a challenge for prebiotic chemical reactions thought to have played a role in the origin of life on Earth. Orbital observations suggest that the combination of sulfate minerals and hematite found in Meridiani rocks may be unusual on the martian surface; however, there is reason to believe that acidity, aridity, and oxidizing conditions were broadly distributed on ancient Mars. When these conditions were established and how much environmental heterogeneity existed on early Mars remain to be determined. Because sulfates and iron oxides can preserve detailed geochemical records of environmental history as well as chemical, textural and microfossil signatures of biological activity, Meridiani Planum is an attractive candidate for Mars sample return.